This method describes how to determine the capacity for water imbibition (moisture uptake) in barley.
Barley intended for the production of malt is evaluated on the basis of its capacity for water imbibition.
Barley is steeped according to a defined scheme, and the absorption of the steeping liquor by the kernels at defined times is determined by calculating the moisture content. The moisture content after 72 h steeping time is used to assess the absorption of steeping liquor or the capacity for water imbibition in barley.
Enrichment of the PAH is performed using solid phase extraction. The extract is obtained from the sample through separation with high performance liquid chromatography on the appropriate stationary phases under isocratic conditions. Detection is conducted with a fluorescence detector. The determination is quite sensitive because these polycyclic aromatic hydrocarbons possess substantial fluorescence properties. Since the fluorescence characteristics of these substances are substance-specific, they are determined using two spectra, the excitation and emission spectra. Thus, selective detection is possible. Through recognition of the specific spectra for each substance and the means of detection at the appropriate wavelengths, maximum sensitivity and selectivity are attainable.
The PAH compounds are concentrated through extraction with cyclohexane and evaporation. The separation is carried out by means of high-performance thin-layer chromatography. The results are evaluated through examination under UV light, followed by comparison of the Rf values with the reference substances.
The method describes how to determine the content of benzo-(a)-pyrene in drinking water using high performance liquid chromatography.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Refer to W-010.06.120 Quantitative Determination of Polycyclic Aromatic Hydrocarbons (PAH) in Drinking Water
The method describes how to determine pesticides and biocidal products in drinking water using high performance liquid chromatography.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The determination is carried out by means of HPLC (refer to W-010.06.120 Quantitative Determination of Polycyclic Aromatic Hydrocarbons (PAH) in Drinking Water).
This method describes how to determine the α-acids and β-acids in hop extract using high-pressure liquid chromatography.
Hop extract intended for use in beer brewing or elsewhere in the food industry